In the field of optical lighting, such as of automotive lighting, requirements are often imposed for the beam pattern in a desired plane or the light intensity distribution along a desired direction. In this case, efforts shall be paid in choosing a suitable design for components in the optical device. For example, in an automotive front lamp, the high beam is normally required to have its biggest intensity at a horizontal position and to decrease gradually in intensity both above and below horizon, such that not only a smooth transition to the low beam is obtained, but also reflections from for example signboards are reduced. Further, in consideration of efficiency and cost, there are also requirements for designs and/or configurations of components in the optical device.
DE102009053581B3 discloses an automotive front-lighting LED matrix light using a primary optics improving homogeneity of light intensity distribution as well as color uniformity. Among other measures, this document proposes a matrix of funnel-shaped light guides for the primary optics, i.e., light guides with curved lower and upper side faces opening towards their light exit side. WO2017015684A1 discloses a similar base system but further develops on a refined groove structuring of the curved side faces.
Still, it is desirable to provide an optical device for automotive lighting, which helps to give a desired beam pattern or light intensity distribution in accordance with actual requirements, while still achieving a high efficiency or usage of light.